Membrane holder



FIG. 1 is a top perspective view of a membrane holder;

FIG. 2 is a front view of the membrane holder;

FIG. 3 is a rear view of the membrane holder;

FIG. 4 is a right side view of the membrane holder;

FIG. 5 is a left side view of the membrane holder;

FIG. 6 is a top view of the membrane holder; and,

FIG. 7 is a bottom view of the membrane holder. 

CLAIM The ornamental design for a membrane holder, as shown and described. 